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McGraw Hill Glencoe Algebra 1, 2012 View details

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Exercise 9 Page 389

Do you remember the formula for finding the area of a circle?

4π m^2

Practice makes perfect

Let's find the area of the circle. The area of a circle with radius r is calculated using the formula below. A=π r^2 From the figure, we know that the radius of the circle is 2m. By substituting 2 for r in the formula, we can calculate A.

A=π r^2

Substitute

r= 2

A=π( 2)^2

CalcPow

Calculate power

A=π 4

CommutativePropMult

Commutative Property of Multiplication

A = 4π

The area of the circle is 4 π m^2.

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Quick Check p.389

Exercise 9 Page 389

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